Pretreatment Carbohydrate Antigen 19-9 Level Indicates Tumor Response, Early Distant Metastasis, Overall Survival, and Therapeutic Selection in Localized and Unresectable Pancreatic Cancer

Abstract

The use of chemoradiotherapy (CRT) for localized and unresectable pancreatic cancer has been disputed because of high probability of distant metastasis. Thus, we analyzed the effect of clinical parameters on tumor response, early distant metastasis within 3 months (DM(3m)), and overall survival to identify an indicator for selecting patients who would benefit from CRT. This study retrospectively analyzed the data from 84 patients with localized and unresectable pancreatic cancer who underwent CRT between August 2002 and October 2009. Sex, age, tumor size, histological differentiation, N classification, pre- and post-treatment carbohydrate antigen (CA) 19-9 level, and CA 19-9 percent decrease were analyzed to identify risk factors associated with tumor response, DM(3m), and overall survival. For all 84 patients, the median survival time was 12.5 months (range, 2-31.9 months), objective response (complete response or partial response) to CRT was observed in 28 patients (33.3%), and DM(3m) occurred in 24 patients (28.6%). Multivariate analysis showed that pretreatment CA 19-9 level (≤400 vs. >400 U/ml) was significantly associated with tumor response (45.1% vs. 15.2%), DM(3m) (19.6% vs. 42.4%), and median overall survival time (15.1 vs. 9.7 months) (p < 0.05 for all three parameters). For patients with localized and unresectable pancreatic cancer, pretreatment CA 19-9 level could be helpful in predicting tumor response, DM(3m), and overall survival and identifying patients who will benefit from CRT.